1. Field of the Invention
This invention relates to an image forming member for electrophotography used for forming images by utilizing electromagnetic waves such as light (the light broadly means ultraviolet ray, visible ray, infrared ray, X-ray, .gamma.-ray and the like).
2. Description of the Prior Art
Heretofore, as photoconductive materials for forming photoconductive layers of electrophotographic image forming members, there have been generally used inorganic photoconductive materials such as Se, CdS, ZnO and the like, and organic photoconductive materials (OPC) such as poly-N-vinylcarbazole (PVK), trinitrofluorenone and the like.
However, the electrophotographic image forming members has still various problems to be solved and therefore, they are now used for electrophotographic image forming processes only under relaxed or compromised operation conditions.
Apart from above, electrophotographic image forming members using a photoconductive layer composed of hydrogenated amorphous silicon (hereinafter referred to as "a--Si:H") have been recently proposed by, for example, German Laid-open (OLS) Nos. 2746967 and 2855718.
The electrophotographic image forming members provided with an a--Si:H photoconductive layer have many advantages over the prior art electrophotographic image forming members. That is, photoconductive layers of any conductive polarity, p-type or n-type, can be produced depending upon the preparation conditions despite amorphous form, and the material does not cause undesirable pollutions, and moreover, the electrophotographic image forming members are of high abrasion resistance due to the high surface hardness, excellent resistance to developing agent, high heat resistance, excellent cleaning propery, high humidity resistance and thus, have good electrophotographic properties.
Though the a--Si:H type electrophotographic image forming members have such many advantages as above, the members still have room for improvement such as photosensitivity at the practical light amount region, gamma value, and dark resistivity.